Molarity is defined as number of moles of solute in 1 L of solution.
Here, 0.1025 g of Cu is reacted with 35 mL of HNO_{3} to produced Cu^{2+} ions.
The balanced reaction will be as follows:
Cu+3HNO_{3}\rightarrow Cu(NO_{3})_{2}+NO_{2}+H_{2}O
From the above reaction, 1 mole of Cu produces 1 mole of Cu^{2+}, convert the mass of Cu into number of moles as follows:
n=\frac{m}{M}
molar mass of Cu is 63.55 g/mol thus,
n=\frac{0.1025 g}{63.55 g/mol}=0.0016 mol
Now, total molarity of solution, after addition of water is 200 mL or 0.2 L can be calculated as follows:
M=\frac{n}{V}=\frac{0.0016 mol}{0.2 L}=0.008 mol/L=0.008 M
Thus, molarity of Cu^{2+} is 0.008 M.
Answer:
C. 64
Explanation:
Given:
The number of equally likely sample outcomes of a single stage = 4
Unknown:
Total number of elements if there are three stages= ?
Solution;
Probability is the likelihood of an event to occur.
In this problem;
For a single stage, the likely outcome is 4
So therefore;
For the 3 stages 4 x 4 x 4 = 64
Therefore, the total number of elements in the sample space of an experiment with 3 stages is 64
Answer:
in particular 69-189 084 = 9283983
Answer:
D. Separating a salt solution by evaporating the water
Explanation:
B. Allowing a nail to rust is a chemical change.
Becuase once the nail rust it turns into flakes and therefore is no longer a nail.
C. building a model rocket propelled by mixing baking soda and vinegar
By mixing baking soda (a powder) into vinegar ( a Acid) it causes a explosion...
the baking soda dissolve into the acid.... This a chemical reaction
A.creating salt by reacting sodium metal and chlorine gas
Sodium is salt but it says.... Sodium metal..... chlorine gas Changes color and it has a strong odor... chlorine gas with sodium metal turns it into salt.... it doesnt stay a metal or a gas it CHANGES.....
so therefore its a Chemical change
When A object or substance changes form or it causes a exsplosion or reaction it is a chemical change.
D. Separating a salt solution by evaporating the water
For a physical change your object may change color or shape but its still the same object.
salt in water ... The salt dont dissolve it just salty water.
So seperating salt by evaporating the water is a physical change.
Mass of substance in grams 60.1
